Hodgkins Lymphoma

3.Contain a small number of scattered mononucleated and multinucleated tumour cells (Hodgkin and Reed-Sternberg cells HRS)

4.Tumour cells are usually ringed by T-lymphocytes in a rosette like manner

Classification

1. Nodular lymphocyte predominant

2. Classical Hodgkins

a)Nodular sclerosing

b)Lymphocyte predominant

c)Mixed cellularity

d)Lymphocyte depleted

Nodular lymphocyte predominant

5% of all cases of Hodgkins

M>F

Usually localised (5-20% present with advanced stage disease)

Morphology

Lymph node architecture replaced by a nodular with or without a diffuse infiltrate predominantly consisting of small lymphocytes, histiocytes and intermingled L&H cells (lymphocytic and or histocytic Reed-Sternberg cell variants).

L&H cells often have multilobated nuclei and are often termed popcorn cells

§In classical Hodgkin’s mature B-cell antigen expression may be low or absent and there is no immunoblobulin production despite gene rearrangements. (due to crippling mutations in the Ig genes or dysregulation of transcription factors)

§Would expect to be prone to apoptosis since normal B-cells are dependent on Ig expression

§Express C-FLIP, a downregulator of Fas may prevent apoptosis

§May also escape apoptosis via the NF-KB pathway

§Classical Hodgkin’s do not express the transcription factor Oct2 or its coactivator BOB1/OBF1

§EBV may also be important in Hodgkins (EBV associated proteins detected in 40% of cases of classical Hodgkin’s – higher rates in the very young and old)